I installed Acrobat 9 Pro, version 9.4.1, one week ago. Since then, in every opened pdf-document appers an grey-and-white-grid-background (see figure below). Normally, I would expect a white background, which I get under this setting only, if I change the background manually to white. How can I change this setting, to get the normally white background as a default? Support is warmly welcome - training_needed